The Globe-Miami mining district in which the Van Dyke project occurs is known mainly for its large porphyry copper deposits, including the Miami-Inspiration, Miami East, Pinto Valley, Copper Cities and Castle Dome mines, and copper-bearing veins of the Old Dominion mine.

The Van Dyke copper deposit lies to the east, and on the hangingwall side, of the Miami fault. The Miami fault is a district-scale northerly-trending, east-dipping normal fault that can be traced from the Van Dyke project to the Copper Cities mine three miles to the north.

The mineralization that comprises the Van Dyke copper deposit has a drill-defined, north-easterly strike length of 1200m, a down-dip dimension of 1300m, and a thickness of approximately 225m.

The Van Dyke deposit is not exposed at surface, therefore all known geological information for the deposit has been gained from exploration diamond drilling programs and from development of the Van Dyke shaft and related level workings.

Mineralization includes both hypogene or primary sulphide, and supergene or secondary enrichment (oxide-silicate+/-sulphide) types, but the latter far outweighs the former in terms of abundance, grade and therefore economic potential.

Secondary copper mineralization comprises the majority of the Van Dyke deposit. Mineralization, consisting primarily of azurite, malachite, chrysocolla, and tenorite occurs principally in tectonically fractured to brecciated panels of Pinal Schist in the hangingwall of the Miami Fault. The secondary minerals occur primarily as bands and crustifications, textures that suggest formation was by filling of open spaces. There are no relict sulphide grains in the upper part of the deposit. Supergene sulfide enrichment occurs in localized pods adjacent to the oxidized mineralization, primarily as chalcocite. Hypogene mineralization occurs beneath the secondary zones.

The secondary copper mineralization that comprises the majority of the Van Dyke copper deposit is believed to have formed from copper laden solutions that migrated laterally and vertically along interconnected fractures and zones of brecciation from the nearby oxidizing copper deposits, making the Van Dyke deposit an Exotic type porphyry copper deposit. In general, the grade of the secondary copper mineralization is at least in part a function of how well the country rock was structurally prepared prior to the mobilization of copper into solution.

The proposed mining method for copper recovery from the Van Dyke deposit is in-situ leaching (ISL). ISL is a proven technology and has been successfully commercially evaluated in Arizona at Santa Cruz.

ISL has been chosen based on the fact that at the Van Dyke mineralization does not support either conventional underground mining or open pit mining due to the close proximity of the deposit to the town of Miami AZ. Further to this, the fractured nature of the host rock, the presence of saturated joints and fractures within the mineralized zone, and copper mineralization that preferentially occurs along fracture surfaces makes the project a good candidate for ISL. The technical criteria listed above are based on scoping level assumptions and will need to be quantified and verified in future studies. 

The in-situ well field will leach and extract copper from the deposit from a series of wells.
The dissolved copper in solution, called pregnant leach solutions, (PLS) will be pumped to the surface for processing.  It is proposed that the well-established Solvent Extraction and Electrowinning (SX-EW) technology will be applied where the copper is removed and deposited as copper cathode.  Once the copper is removed, the solution is recirculated in the well field.  The final product on site is Grade A copper cathode (99.99% pure) for shipment to the market.   

Analysis of in situ leaching included three options, directional drilling from surface, passive drainage from underground galleries, and active pumping from underground. Based on this study, the chosen option is active pumping from underground as the best combination of both lower risk and costs.  Below is a brief summary of each of the three options considered.

The mine development plan is comprised of a ramp access from surface for rubber tired mobile equipment, level development within the targeted production zone, and service and ventilation facilities. These are the following excavations:
- 2,212 metres of ramp 4.9m wide x 4.9m high with arched back driven at a grade of -15%.
- 1,400 metres of level development (galleries) driven at 6.1m wide x 6.1m high.
- Fresh Air Route (Secondary Egress):  This comprises 213 metres of 4.9m diameter borehole raise driven in two segments and connected via 181 metres of 4.9m wide x 4.9m high drifts.
- 1,484 metres of well bays 6.1m wide x 6.1m high.

The Van Dyke ILS Leach Project uses conventional solvent extraction (SX) and Electrowinning (EW) to recover copper from the pregnant leach solution (PLS) it receives from the in-situ leaching operation. Leaching is carried out with weak sulphuric acid bearing solution. 

PLS recovered from the ISL is pumped to the PLS pond and then the SX plant. After the extraction of copper from the PLS the SX plant raffinate is recycled back to the ISL.

The SX plant processes approximately 1,200m3 /h of PLS with an approximate copper concentration of 2.6 grams per liter.  Copper cathode production will total approximately 27,000 tonnes per year from an EW plant.